This invention relates to a device usable with industrial equipment and the like for improving the safety of the equipment operation. The invention is particularly adapted to be employed in conjunction with high speed equipment which is subject to forces that can cause an interruption in the proper operation of the equipment and which can result in damage to persons and/or the equipment if the operation is not terminated in a safe manner.
A particular example of equipment of this type constitutes a pay-out system utilized for purposes of feeding wires, coils or the like to a production line. One example of such a line involves the delivery of wire to equipment designed for making springs or other products. Such lines typically operate at very high speed and require that the wire feeding equipment operate in the same fashion. The equipment ordinarily comprises a large reel holding a considerable length of wire so that the line can operate for a long period of time without interruptions. Thus, the pay-out speed of the wire and the rotational speed of the reel are high in order that the pay-out system can keep up with the line, and this speed is desirably maintained for a considerable time to obtain as much uninterrupted production from the line as possible.
Safety devices in the form of "pull-out" or "breakaway" switches have been used in the past in connection with such industrial equipment. Although not for the same application, U.S. Pat. Nos. 1,162,996 and 3,654,411 generally describe this type of switch. The difficulties encountered in such cases are related to the fact that the switches are designed with parts that separate when subjected to unacceptably high forces. The switch parts are included in the circuit used for the system operation and that circuit is broken and the system shut down when the separation occurs. This is a very abrupt action which only takes place after the unacceptable situation has developed. Danger to employees and/or damage to equipment can still result due, for example, to the momentum of moving parts in the system.